package com.iplay.实战java高并发程序设计.chapter3.c31;

import java.util.Random;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * @author dangwu
 * @since 2021/10/28 4:03 下午
 */
public class ReadWriteLockDemo {
    private static Lock lock = new ReentrantLock();
    private static ReentrantReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    private static Lock readLock = readWriteLock.readLock();
    private static Lock writeLock = readWriteLock.writeLock();
    private int value;
    public Object handleRead(Lock lock) throws  InterruptedException{
        lock.lock();
        try {
            Thread.sleep(1000);
            System.out.println(value);
            return value;
        } finally {
            lock.unlock();
        }
    }

    public void handleWrite(Lock lock,int index)throws InterruptedException{
        lock.lock();
        try {
            Thread.sleep(1000);
            value = index;

        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {
        final ReadWriteLockDemo demo = new ReadWriteLockDemo();
        Runnable readRunnable = () -> {
            try {
//                demo.handleRead(readLock);
                demo.handleRead(lock);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        };
        Runnable writeRunnable = () -> {
            try {
                demo.handleWrite(writeLock,new Random().nextInt());
//                demo.handleWrite(lock,new Random().nextInt());
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        };

        for (int i = 0; i < 18; i++) {
            new Thread(readRunnable).start();
        }
        for (int i = 18; i < 20; i++) {
            new Thread(writeRunnable).start();
        }
    }
}
